John Ars wrote:

If you port Self to Windows, for example, can you legally sell it? In other words, could you charge for a Self IDE?

While I can't give you legally valid advice, the license that comes with Self is very simple. Here is the Self 4.0 version slightly restructured to make it more readable:

You may

use the software internally, modify it, make copies and distribute the software to third parties, including redistribution for profit,

provided each copy of the software you make contains

the copyright notice set forth above, the disclaimer below, and the authorship attribution below.

The Self 4.1 license is almost exactly the same, but it eliminated the "authorship" requirement. This was probably due to the large number of complaints that the BSD license had about a similar clause.

So you see, if you wish to sell the exact same Self that you have freely downloaded from Sun, the license lets you do it legally. Of course, why someone would buy it from you when they can also get it for free is an interesting question.

If you port it to Windows (modify it) and sell it (including redistribution for profit), it seems logical that this would be legal too, though other interpretations are possible. And certainly if you port it to Windows the license does not require you to release your modifications (which some people feel would make it harder to sell it).

Now rather than starting from the Sparc/PPC Self, your port might be easier if it was based on the work Gordon Cichon has done for X86 Linux. In that case, the license is the GPL and you would be required to release all your changes in source form and your port would also have to be released under the GPL. But it would still be perfectly legal for you to sell it.

Thorsten Dittmar has announced a very neat "portfest" to get Self 4.1 running on Linux (X86, I suppose) in January. From the previous discussion in this list, I think they are also planning to use the GPL license but am not certain about this.

I hope this helps, -- Jecel P.S.: thanks for the link for the compiler books. I haven't been able to look at it yet since none of the browsers that I have tried so far seem to be able to cope with this site....